Roof rack assemblies are often secured to vehicle roofs for supporting cargo above the roof. Roof rack assemblies often have longitudinally arranged roof rails. Transverse roof rack bows, sometimes referred to as cross members, may be used to span the distance between the roof rails. Roof rack bows can contribute to aerodynamic drag and wind noise, so some designs allow the bows to be removed from the roof when not in use, or to be stowed in the roof rails. On some vehicles, the distance between the roof rails is greater than the length of the roof rails, making it difficult to stow the roof bows within the roof rails when the roof rack bows are not in use. Telescoping roof rack bows can be difficult for an operator to manually extend so that they reach across the roof between the roof rails.